Wednesday, July 2, 2008

When the Rivers Run Dry

I decided that the plane ride to the wedding this past weekend was the perfect time to start a book I've been wanting to read: When the Rivers Run Dry: Water - The Defining Crisis of the Twenty-First Century. I haven't finished it yet, but it's already given me a lot to think about, and I highly recommend it. It discusses the sources of water, the ways in which many of these sources are being over tapped, and the consequences when that happens. As the author points out, these consequences effect the climate, agriculture, the success of civilizations, the likelihood of war. It was especially interesting to read on my way to Duluth, Minnesota - a city which sits on the edge of Lake Superior, the largest fresh water lake in the world (by surface area).

Duluth is a beautiful city built on the steep hills overlooking the lake, and the lake looks more like an ocean - it has tides, waves, and ship wrecks. But while Phoenix, Arizona is one of the fastest growing cities in the US, Duluth's population was about 105,000 in the 1960s and is now down to about 85,000. Yet Arizona's water resources can't naturally support its population (Phoenix now has a population of about 1.5 million). By classical standards, this pattern of growth is incredibly stupid. Of course, modern strategies allow water to be moved, which is why the Great Lakes states are legislating to ensure the water stays in the region. When the Rivers Run Dry discusses how Arizona is helping the Colorado river to run dry, so while Lake Superior still looks like an ocean, I'm glad the lake states are taking action.

Closer to home, I received the 2007 Drinking Water Quality Report from the DC Water and Sewer Authority today. The water here comes from the Potomac river, which I can walk to. As suspected from the smell of the water in the shower, the water is sometimes over the EPA limit for chlorine. Significantly over. After all, I can smell it. And I wonder - if the water I receive in my posh, white, NW neighborhood is this chlorinated, what's it like in neighborhoods where the residents don't have water filters in their fridges?

Still, the arsenic levels are well under EPA regulations, which is more than can be said for much of the water in India and Bangladesh where millions of people are being slowly poisoned by the water they drink.

While I believe water will become a bit more expensive over time, I fail to see a crisis any time in the future. We are surrounded by water, most of it admittedly salty but with proven means to desalinate it (see Singapore or Israel), we have good technology to recycle lots of it (see Vegas or Singapore) and we waste massive amounts of it so there is lots of room for savings.

anonymous #2 (come on, at least choose pseudonyms!) - indeed, it no longer reaches the sea consistently. i say it's helping to make it run dry since it still sometimes reaches the sea and does, after all, have water further upstream.

anonymous #3 - the problem isn't about a lack of water so much as the location of the water vs. the location of the people and the cost to get that water (especially if it's salty...). it's also about what people do to manage water and how it causes problems - the recent flooding of the mississippi for example (a recent Salon article about this).

the problem isn't about a lack of water so much as the location of the water vs. the location of the people and the cost to get that water (especially if it's salty...).

Does this imply that if we had a massive, cheap energy source (since I imagine energy usage accounts for much of the cost of desalinization and transport of water) would solve the "impending water crisis"?

it's also about what people do to manage water

Can you give other examples of this? It seems the problem of managing the water -- at least in the case of the Mississippi -- is more about businesses and government cutting costs at the expense of other people's homes flooding than it is about any sort of water crisis.

Since you are a computational geometer, I thought that I might ask a question which I recently asked of someone, but never received a reply:

(I recently came across websites devoted to research in computationalgeometry. That field is not represented in my department. Among otherthings, I read the wikipedia article.)

I wanted to verify if myimpressions about it are correct:

Computational geometry research involves exclusively or predominantlytheoretical research. (Grad students working in that area spendatleast 95% of their research time doing theoretical work, not runningexperiments or building systems.) It is mainly algorithms (notcomputational complexity) research, where the algorithms try to solveproblems from geometry. Research in computational geometry mainlyinvolve tools/ techniques used in algorithms research. Knowledge oftopology (a major branch of mathematics) is required.

Josh - I'm not sure (maybe it says that towards the end of the book (; ). But realistically, too much energy/money is needed to solve this problem by just using ocean water, especially since global warming is also a contributer to the rivers running dry since snow caps that cause run offs are not as extensive and "permanent" caches of water like glaciers are melting.

As for the management of water... it's true that it's about governments, mismanagement, etc. But that IS a water crisis, because millions of people don't have access to safe drinking water, live in flood zones, go to war over water rights, etc. The crisis is that people, many of them poor, all over the world live in places which were mostly chosen for their easy and cheap access to water. That water is disappearing.

Anonymous #4 - yes, that's mostly correct though I disagree that a knowledge of topology is a requirement (useful, yes). Also, I'd prefer for this thread not to be hijacked....